Question

tan30°+sin90°+2x²+2x=4x+8

tan5°等于根号几
tan30° cos30° cos45° tan45° cos60° tan60° tan90° cos90°分别等于根号几？

Answer 1

tan30°=√3/3 cos30°= √3/2 cos45°= √2/2 tan45°=1
cos60°=1/2 tan60°= √3 tan90°无意义 cos90°＝0
顺便：
sin0°=0 sin30°=1/2 sin60°=√3/2 sin90°=1